Pilot v2: Core implementation + battery telemetry

Major updates:
- Complete Rust rewrite (pilot-v2/) with working MQTT client
- Fixed MQTT event loop deadlock (background task pattern)
- Battery telemetry for Linux (auto-detected via /sys/class/power_supply)
- Home Assistant auto-discovery for all sensors and switches
- Comprehensive documentation (AVANCEMENT.md, CLAUDE.md, roadmap)
- Docker test environment with Mosquitto broker
- Helper scripts for development and testing

Features working:
✅ MQTT connectivity with LWT
✅ YAML configuration with validation
✅ Telemetry: CPU, memory, IP, battery (Linux)
✅ Commands: shutdown, reboot, sleep, screen (dry-run tested)
✅ HA discovery and integration
✅ Allowlist and cooldown protection

Ready for testing on real hardware.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

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